Drill



Patented Oct. 12, 1937 PAT .L T

DRILL Eugene W.` Everheart, Maestranza, Pachuca, Mexico Application December 12, 1936, Serial No. 115,557 In Mexico January 31, 1936 Claims.

The present invention relates to rock drills and more particularly to lubricators for that type of rock drill employing a pneumatic feed.

In `order to avoid rapid wear and deterioration 5 of pneumatic rock drills it is necessary to provide for their thorough and continuous lubrication. Dueto the conditions under which they are operated and the type of operator usually employed, the lubricating devices for these drills must be so designed as to be certain in operation, free from liability to derangement or breakage, and requiring a minimum of care and ,thought on the part of the operatorv in their maintenance and use.

It is the object of the present invention to provide a lubricator for rock drills using a pneumatic feed which shall be of simple and inexpensive construction, automatic and reliable in action to supply lubricant to the moving parts, and demanding a minimum of attention in use.

To the above ends the present invention contemplates the employment of the feeding movements of the drill at the beginning and ending of the periods of operation to cause the lubricating devices to deliver to the moving parts a predetermined amount of lubricant. The invention also contemplates the use of the supporting and feeding means of such drills for actuating and housing the lubricant supplying and delivering mechanisms.`

In the accompanying drawing which illustrates the preferred form of the present invention as applied to a stoper type rock drill, Fig. 1 shows partly in side elevation and partly in vertical section the complete drill with supporting and feeding devices; Fig. 2 is a vertical section on the line 2 2` of Fig. 1 of the lower portion of the complete drill on an enlarged scale, showing the supporting and feeding mechanisms and the lubricator carried thereby; Fig. 3 is another vertical section on a still larger scale of thev pumping mechanism for delivering thev lubricant from the supply reservoir tothe operative parts of the drill proper; Fig. 4 is a transverse section on the line 4 4 and Fig. 5 a transverse section `on line 5-5 of Fig. 2; and Fig. 6 is a transverse section on line 6-5 of Fig. 3.

Briefly, the stoper'type rock drill illustrated in the drawing comprises the usual body or casing with the customary actuating parts, such as the pneumatic cylinder and piston, supply and eX- haust ports, and hand throttle. This casing or body is supported by a pneumatic cylinder upon a piston with a piston rod extending to rest upon the ground when the drill is used in vertical position. Compressed air is supplied to the pneumatic cylinder to raise the casing with its drill actuating parts to bring the cutting bit into operative engagement with the work and to feed these parts upwardly as the drilling progresses. When the drilling ceases, the compressed air is exhausted from the pneumatic feed cylinder and the casing with its parts descends preparatory to the substitution of another or longer drill or bit or relocation of the apparatus.

The present invention is embodied in this type of drill by making the piston rod for the feed piston hollow at its lower end to form a reservoir for the lubricant, and providing a pump in the reservoir which is actuated by the descent of the casing when the drilling ceases to make its pumping stroke and deliver lubricant to the moving parts.

As shown in Fig. 1, the drill proper comprises a casing Il within which are the usual power cylinder, ports, and valves of common, well known construction and, therefore, not illustrated in the drawing. The cutting drill i3 or bit on the end of the shank I 5 is mounted in the upper end of the casing and driven from the power piston in the well known manner. Compressed air is supplied to the power cylinder through the connection Il, with the throttle valve i9 and rotating handle 2l, all of the usual type.

The means for supporting and feeding the drill proper comprise the pneumatic feed cylinder 23 secured at its upper end to the head 2t of the power cylinder. feed piston 25 made up of the heads 25 and 2l. leather packing rings 28 and disks 29, all clamped upon the solid section 3D of the piston rod bythe nut 3l. Fixed upon the lower portion of the rod is the hollow tubular portion 32 the bottom of which is closed by the sleeve 33 and screw plug or foot 34 having a pointed end to rest securely upon the ground or other abutment and receive the weight and thrust of the drill. A sleeve 35 within the lower end of feed cylinder 23 supports and guides the tubular portions 32 of the piston rod with a sliding t.

Compressed air is supplied to the feed cylinder 23 above the piston 25 through a small passage 36 through the plug 3l' in the head 25 of the power cylinder by the initial opening movement of the throttle to raise the cylinder and the drill proper and thus bring the cutting bit into the desired operative position. Sov long as the drill remains in operation, compressed air will be supplied to the interior of the feed cylinder and the drill will be raised as the bit cuts into the rock. When Within the feed cylinder is the the drilling stops, the compressed air will be exhausted from the feed cylinder and the latter with the drill proper will descend over Ythe piston and piston rod. i

The Vlubricating mechanism is positioned within the feed piston and piston rod, the hollow lower portion 32 having a relatively large bore formingV a chamber or reservoir 38 for the lubricant, access to such reservoir being provided by the removable foot 34.

Positioned within the reservoir at the bottom thereof is the pump comprising the pump casing 39 closed at its lower end by the screw plug or head 49 with inlet opening 4l controlled by the ball check valve 43. The pump casing is supported and held in fixed position by means of the tubular support 45 secured at its lower end in the top of the pump casing, its upper portion extending through an axial bore in thes'olid piston rod section 39 and being clamped thereto at its upper end by screw plug 41. Y A

Within the pump cylinder is the piston 49 hav ing the axial passage 5l whichris Yenlarged at its ,upper end to provide a chamber for ball check valve 53. A tubular pump or piston rod 55 xed inthe upper end of the piston extends upwardly through the tubular support having a sliding t therein.

A coil spring 51 within the pump casing, engaging at its lower'end the head 49 and at its upper endthe pump piston 49, normally tends to move the pump piston upwardly to draw lubricant from the reservoir past the check valve 43 into the pump cylinder. The pump piston is moved in the opposite direction to make its delivery'stroke by means of the tubular pump rod 55, the upper end of whichprojects beyond the feed piston, when the pump piston is raised by the spring 51, and is engaged and actuated by the plug 31 on working cylinder head 24 on'the last portion of the descending movement of the latter following a cessation of the drilling operation.

' In order to conduct to the moving parts the lubricant discharged by the pump, a passage 59 has been provided in the power cylinder head 24, communicating with the passage 36 in the plug 31, and a recess 6I is formed at the lower end of the latterY passage, positioned to receivethe end of the tubular pump rod 55, asshown in Fig. 3.

Thus, with each cessation of the drilling opv erationV a predetermined amount of lubricant is the drill-is turned upside down, the step 34 re- Y Vmoved, and oil or'other lubricant supplied until automatically fed under heavy pressure directly to the workingY parts ofthe drill. Inasmuch as these drills can operate but a very short period of Ytime without stopping for re-adjustment or insertion of a new bit, a thorough and continuous lubrication of the working parts is insured with- 4out requiring any care or attention on the part the reservoir is full. The step is then screwed into place andthe drill is ready to be set up for use. With the step permanently xed in the ground, the drill or bit is Vpresented to the spot to bedrilled andthe throttle vopenedfslightly. This rst movement of the throttle admits air to the pneumatic feed cylinder 23 and the drill casing and attached parts are raised by the feed' cylinder until the bit or drill is in engagement with the rock. As the casing is lifted, the plug 36 on the bottom of the power cylinder head rises and the tubular valve rod 55 and pump piston 49 follow it under the action of the spring 51.

During this upward movement of the pump rod and piston the lubricant enters the pump cylinder 39 until the piston reaches the end of its upward stroke when the the cylinder is lled with lubricant, as shown in 3. Continued upward movement of the drill casing then carries the head 36 out of contact with the pump rod 55 until the engagement of the bit with the rock to be drilled stops further upward movement of the casing and drill. The parts are then in the position shown in Fig. 2.

The drill is now ready for operation, and further opening of the throttle valve will set the power piston in motion and the bit or drill will be advanced into the rock by a succession of hammer blows delivered to it by the power piston.

As the bit penetrates the rock, the casing and drill proper will be correspondingly advanced or fed by the action of the pneumatic feed cylinder and piston. Y

When the bit has penetrated as far as desired or practicable, the throttle will be closed to stop operation of the drill and immediately the compressed air will be exhausted from the feed cylinder 23 to permit the drill to descend with its feed cylinder telescoping over the feed piston and rod. Just before the casing or drill reaches the limit of. its downward movement the plug 31 contacts the projecting end of tne tubular pump 55 and forces the latter downwardly, causing the pump to make its delivery stroke, discharging the lubricant through the tubular rod and passages 3S and 59 into the power cylinder from which it is distributed to the various moving parts preparatory to the next operation of the drill. Thus each time the drill is stopped, even if only momentarily, the pump will discharge the predetermined amount of lubricant Vto the actuating parts.

Due tothe fact that drills of this type are usually designed to be operated at approximately the height of a mans waist or even higher, they are provided with a feed cylinder of very considerable length, thus affording opportunity in the hollow piston rod for a reservoir of large capacity for the lubricant so that there is no' likelihood that the lubricant can become exhausted during any one period or shift in operation.

Any lubricant which may escape into the feed cylinder, due to imperfect fit of the upper end of the tubular pump rod in the recess in the end of the head or plug, or for other reason, will serve to lubricate the feed cylinder and piston in their movements relative to one another, and also to lubricate the tubular pump rod in itsreciprocations within the tubular support 45 for the pump casing.

The lubricator herein shown and described may be easily applied to standard and commercial forms of this Ytype of rock drill merely by substituting a new feed piston and parts for the old ones with which such machines areroriginally supplied, boring if necessary the passages to conduct the lubricant from the pump rod to the power cylinder. Due to the fact that all the parts of the new lubricator are contained within the feed cylinder, they are fully protected from dust and dirt and accidental injury. Y

While the present invention has been shown and described in connection with a certain type of rock drill, it is to be understood that its use is not necessarily limited to this type only, but may be embodied in other drills for which it is adapted. Nor is the present invention limited to the specific forms of the several parts as herein shown, but these may be varied in their form and arrangement within the scope of the appended claims.

Having thus described the invention, what is claimed is:

1. In a drill, the combination with a casing and drill-actuating devices carried thereby, of means for feeding the casing, and mechanism responsive to the movement of the casing for delivering lubricant to the drill-actuating devices.

2. In a drill, the combination with a casing and drill-actuating devices carried thereby, of means for moving the same toward and from the work, and mechanism actuated by the movement of the casing for delivering lubricant to the drill-actuating devices.

3. In a drill, the combination with a casing and drill-actuating devices carried thereby, oi means for controlling the movements of the casing toward and from the work, and mechanism actuated by the movement of the casing from the work for delivering lubricant to the drillactuating devices.

4. In a drill, the combination with a casing and drill-actuating devices carried thereby, ci pneumatic means for feeding the casing, sai-d means having a reservoir for lubricant, and a plump associated with said means and actuated With the feeding and return movements of the casing for delivering lubricant from the reservoir to said casing and devices.

5. In a drill, the combination with a casing and drill-actuating devices carried thereby, of a pneumatic cylinder with piston and piston rod for feeding the casing and devices, the piston rod being hollow yfor a portion of its length to provide a reservoir for lubricant, and a pump within the piston rod and actuated in accordance with the feed and return movements of the cylinder for delivering lubricant from the reservoir to the casing and devices carried thereby.

6. In a pneumatic drill, the combination with a casing and drill-actuating devices carried thereby, of a pneumatic cylinder with piston and piston rod for feeding the casing and devices, the piston rod being hollow at its lower portion to provide a reservoir for a supply of lubricant and having an axial bore through its upper end, a lubricant pump in the reservoir, and a tubular pump actuating rod extending through the axial bore in the piston rod for actuating the pump and for directing the lubricant to the casing and devices carried thereby.

'7. In a pneumatic drill, the combination with a casing and drill-actuating devices carried thereby, of a pneumatic cylinder with piston and piston rod for feeding the casing and devices, the piston rod being hollow at its lower portion to provide a reservoir for a supply of lubricant and having an axial bore through its upper end, a lubricant pump in the reservoir, a tubular support for the pump secured in the bore of the piston, and a tubular pump actuating rod extending through the tubular support and movable therein for actuating the pump and for directing the lubricant to the drill-actuating devices.

8. In a pneumatic drill, the combination with a casing and drill-actuating devices carried thereby, of a pneumatic cylinder with piston and piston rod for feeding the casing and devices, the piston rod being hollow at its lower portion to provide a reservoir for a supply of lubricantand having an axial bore through its upper end, a lubricant pump cylinder positioned in the reservoir, a pump piston, an actuating rod for the pump piston mounted in the feed piston to slide longitudinally thereof, a spring for raising the pump piston and rod to draw lubricant into the pump cylinder from the reservoir and to cause the upper end of the rod to project into the path of movement of the feed cylinder during the feeding movement of the latter, in position to be actuated thereby on its return movement to cause the pump piston to make its delivery stroke.

9. In a pneumatic drill, the combination with a casing and drill-actuating devices carried thereby, of a pneumatic cylinder with piston and piston rod for feeding the casing and devices, the piston rod being hollow at its lower portion to provide a reservoir for a supply of lubricant, and a removable plug at the lower end of the hollow piston to close the same and to support the drill when in operation.

10. In a pneumatic drill, the combination with a casing and drill-actuating devices carried thereby, of a pneumatic cylinder and cooperating piston and piston rod, the cylinder and the piston and rod being relatively movable and constituting feeding means to feed the casing and devices carried thereby, certain of the feeding means being provid-ed with a reservoir for lubricant and with pumping mechanism actuated by relative movement of said means to deliver lubricant from the reservoir to the drill-actuating devices.

EUGENE W. EVERHEART. 

